1. Field of the Invention
The invention relates to an insulating covering for placement over a conductive splice of an electrical flat power cable, particularly electrical flat power cables which are for placement on the floor and beneath the carpet.
2. Description of the Prior Art
It is commonplace in such structures as office buildings and the like to have electrical power cable routed within the building, on the floor of the building and beneath the carpeting; so-called undercarpet power cable. This type of cable power system is advantageous in office buildings where modular offices are likely, and where the relocation of people is commonplace. For example, the electrical power cable is typically run within the walls of the office buildings in a manner typically found in all structures, including homes or residences, with the use of round conductors. However, at the interface of the walls and the floor, a transition to flat undercarpet power cable is made, and the flat cable is actually placed beneath the carpet. In all likelihood, the carpeting is not permanent carpeting as we know it, where the carpeting is tacked to the edges of the walls, but rather is squares of carpeting which are semi-adherent to the floor but yet can be lifted or pulled off of the floor for access to the electrical cabling which rests upon the floor. Such systems are described more fully in U.S. Pat. Nos. 4,319,075 and 4,417,096, incorporated herein by reference.
In such systems, it is typically required to splice the ends of flat undercarpet power cable to an end of a new section of cable. Such splices are commonly made with a metallic splice member having insulation piercing contacts which effect an electrical connection from one cable to the next. Such conductive splices are shown in U.S. Pat. No. 4,560,224, incorporated herein by reference. The cables are routed to local access points within the building which require the power. More specifically, floor mounted duplex receptacles are included within the system and are interconnected to the flat undercarpet power cable. A flat metallic ground plane is then placed over the top of the flat undercarpet cable.
An advantage of such a system is found in the replacement and/or ease of changing electrical requirements within the building due to relocation or changing power requirements. It should be appreciated that the carpet squares can merely be uplifted for accessing the power cable, and further cable sections can be added or rerouted to other areas of the building where the power is needed.
While the thickness of the cable is advantageous for placement beneath the carpet, making such systems easily installable, there are also disadvantages to this system. A disadvantage to having such a system is that, due to the location of the cable, a splice cannot be merely made as in conventional round wire circuits, that is, by merely adding another junction box within the wall and making the splice within the box. Having a plurality of junction boxes within the floor of the building would negatively affect the very advantage of the system. It should also be appreciated that the splicing of electrical cables must also meet standards within the industry, such as U.L. and NEMA, in addition to standards which are set by local authorities.
Three requirements must be met when considering such a covering for conductive splices. First, the conductive splice must be sealed from atmospheres such as moisture. Given that these flat cables are placed upon the floors of buildings, it must be assumed that water would, at some point, be present on the floor. Thus, these coverings must be able to be sealed from atmospheres of water. Second, the coverings must electrically insulate the conductive splice members from the ground shield which is placed over the cable. Third, the coverings must offer some type of physical protection from the activity which takes place above the carpet. For example, heavy desks and cabinets are placed on top of the carpet and on top of the cable and the coverings must withstand such abuses.
The present method of making such a splice is to use a splice covering which includes a gelatinous material enclosed within two insulating sheets. The insulating sheets are adhered at side edges thereof to seal the gelatinous material therein. The gelatinous material is nonconductive and seals the interior of the covering from the entry of water. The gel is so viscous that even if the side edges of the insulating sheets allow water therein, the water could not permeate through the gel to a position where it would react with the conductive splice members on the cable. The insulating sheets themselves perform the other two requirements of the splice covering; that is, they protect the interior splice from the activity above the carpeting, and they insulate the splice member from the ground shield placed above the flat cable. While this insulating mechanism is adequate for all purposes, the insulator is somewhat cumbersome to use, that is, in coordinating this gelatinous material while yet attempting to place the insulating coverings over the splice.